01/08/2007 Council Packet - Laserfiche WebLink

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• • • Anoka County Multi- Jurisdictional All Hazards Mitigation Plan Fire Risk: The combined effects of blast overpressure damage and the thermal pulse or fireball can ignite combustible materials, causing sustained fires. Primary fires are those ignited directly by the thermal pulse. Secondary fires are generated by damage and destruction from blast overpressures and result from the disruption of furnaces and gas and electric lines. Fallout risk: A nuclear explosion near the ground makes a big crater. Earth from the crater is changed from solids into hot gas and fine dust. This hot gas and dust, together with vaporized materials, form a giant fireball that rises rapidly and becomes the top part of the nuclear mushroom cloud. The heavier particles of earth become the stem of the mushroom cloud. The earth in the stem and in the mushroom cloud becomes radioactive. The top of the mushroom is a cloud of fine particles. The heavier, larger particles settle close to the point of explosion, the small particles float several hundred miles in the wind. The first 24 hours is the most dangerous period as the initial fallout is highly radioactive. The delayed fallout particles lose much of their radioactivity and reaches earth in rain or snow over periods ranging from days to years. The three kinds of dangerous radiation in fallout are alpha, beta and gamma. Gamma radiation penetrates the body, causing damage to organs, blood and bones. Large doses of gamma radiation can cause sickness or death. Small doses incurred over a long period of time may not have an immediate effect, but may cause various forms of illness later in life. Genetic damage in subsequent generations may also result. Alpha radiation is stopped by the outer skin layers and does not usually present an external hazard. However, if contaminated air, food, or water enters the body in sufficient quantity, considerable internal damage can occur. Beta radiation is more penetrating and may cause burns where fallout particles have deposited on the skin. The effects of a nuclear attack have varying effects on populations. Those people located near the explosion would be killed or seriously injured by the blast, heat, or initial nuclear radiation. People a few miles away would be subject to blast, heat, and fires. A high percentage of the population residing in the lighter damaged areas would probably survive, but might subsequently be endangered by radioactive fallout. 4.2.2.2 Civil Disturbance /Strikes/Workplace Violence Civil disorder is defined as any incident intended to disrupt community affairs and threaten the public safety. Civil disorders include: riots mob or strike violence, and any demonstration resulting in police intervention and arrests. Workplace Violence is defined as employees who are exposed to the use of harassment, intimidation, physical force, or the abuse of power or authority, where the intent is to control by causing pain, fear or hurt. 4.2.2.3 Dam /Levee Failure A dam /levee is a barrier constructed across a watercourse for the purpose of storage, control, or diversion of water. Dams generally fall into the following categories Earth Dams make up the vast majority of dams and are safe if they are properly constructed and maintained. Concrete Gravity Dams are designed to resist sliding and shaped to resist overturning. Arch Concrete Dams are used to narrow sites and have strong abutments. Gravity Arch Concrete Dams are a conservative design of the Arch. Buttress Concrete Dams have a strong foundation and are resistant to sliding, overturning and overflowing.